this research was conducted to evaluate the effect of mild and intense drought stresses on root traits and some anti-oxidative enzymes and to identify drought tolerant genotypes in tall fescue. twenty-four genotypes were assessed under three levels of moisture regime (control, mild and intense drought stresses) according to a factorial experiment based on a completely randomized design with thr...

We analyze the interannual monthly variability of oxygen isotope ratios in data from IAEA stations along the Atlantic coast of South America between 238 and 348 S to evaluate the influence of parameters such as temperature, rainfall amount and moisture source contribution on meteoric water recharging two karst systems in subtropical Brazil. In addition, a 2 year monitoring program performed on ...

In the boreal region, soil organic carbon (OC) dynamics are strongly governed by the interaction between wildfire and permafrost. Using a combination of field measurements, numerical modeling of soil thermal dynamics, and mass-balance modeling of OC dynamics, we tested the sensitivity of soil OC storage to a suite of individual climate factors (air temperature, soil moisture, and snow depth) an...

We introduce an objective definition for onset and withdrawal of the South Asian summer monsoon (SASM), based on the large-scale atmospheric moisture budget. The change point (CHP) index allows precise characterization of the different stages and timescales of the large-scale SASM and is highly correlated with the local operational index, the monsoon onset over Kerala. The CHP-based onset and w...

A series of large-eddy simulations (LES) of non-precipitating cumulus clouds over land was performed. These simulations were idealized from observed conditions at the Southern Great Plains ARM site on 21 June 1997 and were intended to investigate the effect of initial soil moisture on the structure of the cloudy boundary layer. The surface fluxes were either dominated by latent heat or sensible...

An increased ability to analyze landscapes in a spatial manner through the use of remote sensing leads to improved capabilities for quantifying human-induced forest fragmentation. Developments of spatially explicit methods in landscape analyses are emerging. In this paper, the image delineation software program eCognition and the spatial pattern analysis program FRAGSTATS were used to quantify ...

Stomatal responsiveness to evaporative demand (air vapour pressure deficit (VPD)) ranges widely between species and cultivars, and mechanisms for stomatal control in response to VPD remain obscure. The interaction of irrigation and soil moisture with VPD on stomatal conductance is particularly difficult to predict, but nevertheless is critical to instantaneous transpiration and vulnerability to...

Oviposition by northern corn rootworms, Diabrotica barberi Smith and Lawrence, and western corn rootworms, Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae), key pests of corn in the Great Plains of the USA, occurs in the soil during late summer. Overwintering eggs are exposed to variable soil moisture and temperatures below − 5 ° C. The winter mortality of eggs in the soil is ...

Unique oil:sand aggregates, termed surface residue balls (SRBs), were formed on coastal headland beaches along the northern Gulf of Mexico as emulsified MC252 crude oil mixed with sand following the Deepwater Horizon spill event. The objective of this study is to assess the biodegradation potential of crude oil components in these aggregates using multiple lines of evidence on a heavily-impacte...

Recent observational analysis reveals the central role of three cloud types, congestus, stratiform, and deep-convective cumulus clouds, in the dynamics of large scale convectively coupled Kelvin waves, westward propagating 2-day waves, and the Madden–Julian oscillation. Recently, a systematic model convective parametrization highlighting the dynamic role of the three cloud types has been develo...